title: The prognostic impact of obesity on molecular subtypes of breast cancer in premenopausal women.
abstract: OBJECTIVE
  The increasing incidence of obesity throughout the world will result in expansion of the number of women at risk for developing breast cancer. Obesity is associated with adverse outcomes in postmenopausal women with breast cancer. In premenopausal women, the association is less clear. We investigated the impact of obesity on tumor features, hormonal status, recurrence and mortality in premenopausal breast cancer patients, classified according to molecular subtypes.
  
  
  METHODS
  818 premenopausal women with nonmetastatic breast cancer were analysed. Patients were classified into 3 groups according to body mass index (BMI): i) normal body weight (BMI: 18.5-24.9 kg/m(2)); ii) overweight (BMI: 25-29.9 kg/ m(2)); and iii) obese (BMI:>30 kg/ m(2)). Clinocopathologic characteristics and survival rates were analyzed for triple negative, HER-2 overexpressing and luminal subtypes.
  
  
  RESULTS
  Obese patients compared with normal-weight women were older at diagnosis (p<0.001) and more often had high grade tumor (57.1 vs 42.3%; p=0.04) with lymphovascular invasion (79.5 vs 63.9%; p=0.03). The median follow-up period after diagnosis was 29 months. According to the molecular subtypes, overall survival (OS) and disease free survival (DFS) were significantly shorter in obese patients with triple negative breast cancer (TNBC) (p=0.001 and p=0.006, respectively). Obesity (HR 1.4; 95% CI 1.0-2.1; p=0.04) and lymphovascular invasion (HR 2.1; 95% CI 1.3- 3.3; p=0.02) were found to be independent prognostic factors for TNBC mortality.
  
  
  CONCLUSIONS
  Obesity is associated with estrogen (ER) and progesterone receptor (PR) negative tumors and poor OS in premenopausal women with breast cancer.
authors.affiliation: Department of Medical Oncology, Hacettepe University Cancer Institute, Ankara, Turkey.
authors.forename: F P
authors.initials: FP
authors.lastname: Turkoz
authors.forename: M
authors.initials: M
authors.lastname: Solak
authors.forename: I
authors.initials: I
authors.lastname: Petekkaya
authors.forename: O
authors.initials: O
authors.lastname: Keskin
authors.forename: N
authors.initials: N
authors.lastname: Kertmen
authors.forename: F
authors.initials: F
authors.lastname: Sarici
authors.forename: Z
authors.initials: Z
authors.lastname: Arik
authors.forename: T
authors.initials: T
authors.lastname: Babacan
authors.forename: Y
authors.initials: Y
authors.lastname: Ozisik
authors.forename: K
authors.initials: K
authors.lastname: Altundag
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000737:chemistry* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality; D017697:Premenopause; D016016:Proportional Hazards Models; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human